1 //===-- llvm/MC/MCELFObjectWriter.h - ELF Object Writer ---------*- C++ -*-===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 10 #ifndef LLVM_MC_MCELFOBJECTWRITER_H 11 #define LLVM_MC_MCELFOBJECTWRITER_H 12 13 #include "llvm/ADT/Triple.h" 14 #include "llvm/Support/DataTypes.h" 15 #include "llvm/Support/ELF.h" 16 #include <vector> 17 18 namespace llvm { 19 class MCAssembler; 20 class MCFixup; 21 class MCFragment; 22 class MCObjectWriter; 23 class MCSectionData; 24 class MCSymbol; 25 class MCValue; 26 27 class MCELFObjectTargetWriter { 28 const uint8_t OSABI; 29 const uint16_t EMachine; 30 const unsigned HasRelocationAddend : 1; 31 const unsigned Is64Bit : 1; 32 const unsigned IsN64 : 1; 33 34 protected: 35 36 MCELFObjectTargetWriter(bool Is64Bit_, uint8_t OSABI_, 37 uint16_t EMachine_, bool HasRelocationAddend, 38 bool IsN64=false); 39 40 public: getOSABI(Triple::OSType OSType)41 static uint8_t getOSABI(Triple::OSType OSType) { 42 switch (OSType) { 43 case Triple::FreeBSD: 44 return ELF::ELFOSABI_FREEBSD; 45 case Triple::Linux: 46 return ELF::ELFOSABI_LINUX; 47 default: 48 return ELF::ELFOSABI_NONE; 49 } 50 } 51 ~MCELFObjectTargetWriter()52 virtual ~MCELFObjectTargetWriter() {} 53 54 virtual unsigned GetRelocType(const MCValue &Target, const MCFixup &Fixup, 55 bool IsPCRel) const = 0; 56 57 virtual bool needsRelocateWithSymbol(unsigned Type) const; 58 59 /// @name Accessors 60 /// @{ getOSABI()61 uint8_t getOSABI() const { return OSABI; } getEMachine()62 uint16_t getEMachine() const { return EMachine; } hasRelocationAddend()63 bool hasRelocationAddend() const { return HasRelocationAddend; } is64Bit()64 bool is64Bit() const { return Is64Bit; } isN64()65 bool isN64() const { return IsN64; } 66 /// @} 67 68 // Instead of changing everyone's API we pack the N64 Type fields 69 // into the existing 32 bit data unsigned. 70 #define R_TYPE_SHIFT 0 71 #define R_TYPE_MASK 0xffffff00 72 #define R_TYPE2_SHIFT 8 73 #define R_TYPE2_MASK 0xffff00ff 74 #define R_TYPE3_SHIFT 16 75 #define R_TYPE3_MASK 0xff00ffff 76 #define R_SSYM_SHIFT 24 77 #define R_SSYM_MASK 0x00ffffff 78 79 // N64 relocation type accessors getRType(uint32_t Type)80 uint8_t getRType(uint32_t Type) const { 81 return (unsigned)((Type >> R_TYPE_SHIFT) & 0xff); 82 } getRType2(uint32_t Type)83 uint8_t getRType2(uint32_t Type) const { 84 return (unsigned)((Type >> R_TYPE2_SHIFT) & 0xff); 85 } getRType3(uint32_t Type)86 uint8_t getRType3(uint32_t Type) const { 87 return (unsigned)((Type >> R_TYPE3_SHIFT) & 0xff); 88 } getRSsym(uint32_t Type)89 uint8_t getRSsym(uint32_t Type) const { 90 return (unsigned)((Type >> R_SSYM_SHIFT) & 0xff); 91 } 92 93 // N64 relocation type setting setRType(unsigned Value,unsigned Type)94 unsigned setRType(unsigned Value, unsigned Type) const { 95 return ((Type & R_TYPE_MASK) | ((Value & 0xff) << R_TYPE_SHIFT)); 96 } setRType2(unsigned Value,unsigned Type)97 unsigned setRType2(unsigned Value, unsigned Type) const { 98 return (Type & R_TYPE2_MASK) | ((Value & 0xff) << R_TYPE2_SHIFT); 99 } setRType3(unsigned Value,unsigned Type)100 unsigned setRType3(unsigned Value, unsigned Type) const { 101 return (Type & R_TYPE3_MASK) | ((Value & 0xff) << R_TYPE3_SHIFT); 102 } setRSsym(unsigned Value,unsigned Type)103 unsigned setRSsym(unsigned Value, unsigned Type) const { 104 return (Type & R_SSYM_MASK) | ((Value & 0xff) << R_SSYM_SHIFT); 105 } 106 }; 107 108 /// \brief Construct a new ELF writer instance. 109 /// 110 /// \param MOTW - The target specific ELF writer subclass. 111 /// \param OS - The stream to write to. 112 /// \returns The constructed object writer. 113 MCObjectWriter *createELFObjectWriter(MCELFObjectTargetWriter *MOTW, 114 raw_ostream &OS, bool IsLittleEndian); 115 } // End llvm namespace 116 117 #endif 118